Rep. Darrell Issa's decision to press on with his House panel's Benghazi investigation, despite the creation of a new select committee to look into the 2012 terror attack in Libya, is an indication the California Republican is "going rogue," a leading Democrat said Tuesday.

Rep. Elijah E. Cummings said that Issa, chairman of the House Oversight and Government Reform Committee, is undermining the new special select committee created by Speaker John A. Boehner and chaired by Rep. Trey Gowdy, R-S.C. "I think he is going rogue," Issa, the ranking Democrat on the Oversight Committee, said in an appearance on MSNBC's "Politics Nation" with Al Sharpton. "I actually believe that Chairman Issa is out of control, I really believe that."

The Oversight Committee, under Issa's leadership, has been conducting its own probe of Benghazi, and will hear testimony from Secretary of State John Kerry on June 12.

Boehner, announcing the new select committee earlier this month, said in a statement that it was time for the House "to respond as one institution, and establish one select committee. A committee with robust authority. A committee that will do its work while the House continues to focus on the people’s priorities."

Issa and Cummings have had high-profile clashes on the Oversight Committee on Benghazi and other issues.